Method and apparatus for producing wool-like yarn from synthetic fibers



y 1962 KIKUlCHl TSUTSUMI METHOD AND APPARATUS FOR PRODUCING WOOL-LIKE YARN FROM SYNTHETIC FIBERS Filed Feb. 25, 1960 a W M 3,046,632 METHOD AND APPARATUS FOR PRODUCING WOOL-LIKE YARN FROM SYNTHETIC FIBERS Kikuichi Tsutsumi, Higashisumiyoshi-ku, Osaka-shi, Japan Filed Feb. 23, 1960, Ser. No. 10,150 Claims. (Cl. 28-1) This invention relates to the manufacture of wool-like synthetic fibers such as woollie nylon and to a device and method for manufacturing them involving a procedure wherein the crimped yarn of a synthetic fiber is prepared by a known method, the yarn is passed through the contact surface of an electric insulating block or another similar block to generate static electricity on the fiber, and then the yarn is heat-set under conditions in which each filament snarls because of the electricity.

Most synthetic fibers have been given their woolly feel by a twisting finish. Cloths made of highly twisted fibers of this kind are not suitable for making an undershirt which should not give a strained feel to its wearer while those having a small degree of twist do not give such feel but rather they give hard or rough touch far from such a soft feel as in wool. Moreover the apparatus and processes for making the fiber by twisting are complicated, costly and not suitable for its mass production.

According to the method of this invention, these disadvantages have been overcome and synthetic fiber with a soft feel like wool can be obtained by a simpler apparatus and processes and by a method of mass production.

An object of this invention is to obtain a yarn of synthetic fibers with a soft and woolly feel not seen in the fibers made by the method using a twist finish.

Another object of this invention is to provide a method of manufacturing a yarn of synthetic fibers with a soft feel comprising procedures wherein yarn of the fiber is rubbed between two blocks made of electric insulators to generate static electricity thereon and is then heat-set while each filament is in an irregularly curved state due to the repulsive force of the electricity.

Another object of this invention is to provide a manufacturing apparatus for a yarn of synthetic fibers, comprising a device for supplying raw yarn of the crimped synthetic fiber, a device to generate static electricity on the fiber by rubbing it on an electric insulator, and a device to heat-set the charged fiber. The device for the heat-setting includes a heater and a plate having an arc shape on which the fiber is heat-set.

Still another object of this invention is to provide a device for generating static electricity on the fiber, comprising a lower base block made of abrasion resistant plastic upon which the yarn will slide, an upper block made of elastic material such as gum which will push the yarn against the base block to generate electricity and irregularity in each filament, and two guides for the yarn to slide on the base block as the yarn is drawn downwardly.

A further object of the invention is to provide a method of producing a yarn of crimped synthetic fibers by impressing on a crimped untwisted yarn having the 3,046,632 Patented July 31, 1962 ice fibers free from the tension in direction of the yarn,

fibers close together a friction produced static charge for FIG. 4a is a representation of the synthetic fibers manufactured by the method of this invention without a twisting finish, and

FIG. 4b is a representation of the yarn made of the synthetic fibers of this invention.

Referring to an apparatus shown in FIG. l, a spindle 1 rotates at the speed of 600 r.p.m. Yam 2 of crimped synthetic fibers is coiled around a wood bobbin 3 which is fixed on the spindle 1. A guide 4 for the yarn is fixed to a frame. Two guides 5 and 6 for the yarn are located at such positions as to make the crimped yarn rub against the top surface of a lower base block 7 made of abrasion resistant plastic. When the yarn is being passed across the surface of the base block 7 an upper block 8 made of gum always presses the yarn against the base block 7. A simple way in which to mount blocks 7 and 8 is shown in FIGURE 1a in which lower block 7 is mounted in a holder 7a fixed to the frame F, and upper block 8 is mounted on a holder 8a pivoted to holder 7a at one end and engageable with holder 7a at the other end so that block 8 will be held in position slightly spaced from block 7. While the yarn slides through the interstice between the upper and lower blocks 8 and 7 a static electricity charge is generated on the yarn and its filaments are disengaged from each other to some extent. At this time the filaments tend to separate from each other due to the repulsive force of the generated electricity as shown in FIG. 3. The filaments treated in the first crimping operation lie together in nearly parallel lines as shown in FIG. 2, but after the treatment to generate the electricity they will be'rufiled with an irregular wave in each filament as shown in FIG. 3. The yarn thus treated is passed through the guide 6 and a device '9 for heat-setting. The device 9 has a plate with an arc shape and a heater 10 in the interior of the device heated to a temperature of about 150 C. When the yarn with the electric charge thereon slides on the surface of the plate of the device 9 it will be, heat-set in its arbitrary waved state. The yarn is then passed through a free guide 211 to a winding. bobbin 12 which rotates at a constant peripheial speed. The rotation is transmitted from a transmission roller 13. Examples of methods of producing these yarns will be illustrated as follows.

Example 1 Nylon yarn composed of 15 filaments of 14 denier is twisted at 30 t./m. and set for the crimping operation, at which time an additional 5 t./m. twisting is givento give a total of 35 t./m. to the twisted yarn. This yarn is heat-set at a temperature of C. for 30 min. The set yarn is disengaged to obtain the yarn shown in FIG. 2.

The filaments are parallel to each other and assembled electricity generated by the rubbing of the yarn between the two insulators, each filament repulses others and is in the state shown in FIG. 3. The average wave length of this filament is 2.5 times longer than that of the raw crimped filament because of the drawing, friction and setting. The static electricity on the yarn is then grounded through a drum 20 made of stainless steel. Though the electricity on the yarn is thus discharged, its irregular wave is already set and each filament is not in parallel, as seen in FIG. 4a. The yarn is then wound on a bobbin with suitable tension of the yarn. The wound yarn is finally heat-set at the temperature of 120 C. for min., to obtain the wool-like yarn of synthetic fibers which is the object of this invention. If necessary, an antistatic agent is applied to the yarn product. The product has a soft woolly feel and is suitable for knitting. In case it is necessary to dye the yarn, thedyeing temperature is lower than that of the final heat-setting and accordingly the heat-set state will not be changed by the dyeing process.

Example 2 Yarn composed of filaments of nylon (15 denier) is given a twist of 1 twist per inch in one direction. This yarn is woven for the crimping operation and heat-set at the temperature of 100 C. and then disengaged to obtain deeply crimped yarn. This is raw material in this example. The raw yarn is untwisted completely by twisting it back in the other direction by a twisting machine and completely untwisted yarn is obtained. At the same time the yarn is passed through the space between the blocks 7 and 8 in FIG. 1 and slides on the top surface of the device 9 in FIG. 1 heated to 150 C. The yarn is heat-set at a temperature of 90 C. during the sliding. The resulting yarn is irregularly waved as shown in FIG. 3. The average wave length of the filament is far longer than that of raw crimped fibers. Then the static electricity is discharged and the fibers return to the usual state. But the ruffied fibers retain their irregularity. Two or more yarns thus produced are assembled and twisted. The resulting product is shown in FIG. 45. It may be wound on a bobbin with a suitable tension of the yarn and finally heat-set at a temperature of 120 C. The yarn of synthetic fibers having a woolly feel results. The product has similar excellent properties as mentioned in Example 1.

This invention is not limited to the above examples and is limited only by the following claims.

I claim:

1. Apparatus for manufacturing yarn of crimped synthetic fibers, comprising supply means for supplying crimped untwisted yarn having fibers close together, block means at least partly of electrically insulating material, yarn guide means guiding the crimped untwisted yarn from said supply means over said block means for generating a charge of static electricity on the yarn fibers, means for heat setting the electrically charged yarn over which the yarn passes after it passes over said block means, and a collecting means receiving and collecting yarn from said heat setting means.

2. Apparatus as claimed in claim 1 in which said block means comprises a base block of abrasion resistant and electrically insulated plastic, an upper block of elastic electrically insulating material opposed to and spaced slightly from said base block, said upper block pushing the yarn against the opposing surface of the base block, and said yarn guide means comprising two yarn guides, one on each side of said base block and guiding the yarn against the base block.

3. Apparatus as claimed in claim 1 in which said heat setting means comprises a heater and an are shaped heat conducting plate around said heater and over which plate said yarn is guided.

4. A method of producing a yarn of crimped synthetic t fibers, comprising generating on a crimped untwisted yarn a friction produced static electric charge for causing the fibers to spread apart due to the repelling force of the charge, heat setting the yarn with the fibers thus spread apart, and removing the static charge from the set yarn.

5. A method of producing a twine from a plurality of untwisted yarns composed of crimped synthetic fibers, comprising generating on each crimped untwisted yarn a friction produced static electric charge for causing the fibers to spread apart due to the repelling force of the charge, heat setting the yarn with the, fibers thus spread apart, and removing the static charge from the set yarn, twisting said plurality of yarns together while maintaining them under tension, and finally heat setting the twisted together yarns.

References Cited in the file of this patent UNITED STATES PATENTS 2,158,415 Formhals May 16, 1939 2,468,827 Kennedy et a1. May 3, 1949 2,711,626 Oglesby et al. June 28, 1955 2,740,184 Thomas Aug. 3, 1956 2,852,906 Breen Sept. 23, 1958 2,956,328 Faw Oct. 18, 1960 2,964,900 Hicks Dec. 20, 1960 

